This is the opening phrase to indicate that a fictitious story is to follow.

Girlfriend: Oh no you didn't, what is all that white stuff on your boxers... ain't from me brotha!
Lying ass nigga: What had happened was there was a fire at the club and the white stuff that come out the fire extingisher got all my boxers... cus you know baby, I sag a little bit. Then I was tryna get home to you cus I didn't wanna be out all night... and then I didn't have time to wash my boxers off.